/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id$
 */
package wx.xml.xalan.xml.utils;

import org.w3c.dom.Attr;
import org.w3c.dom.Document;
import org.w3c.dom.Element;
import org.w3c.dom.Node;
import org.xml.sax.InputSource;

import java.io.IOException;

import javax.xml.parsers.DocumentBuilder;
import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.parsers.ParserConfigurationException;
import javax.xml.transform.TransformerException;

/**
 * @deprecated Since the introduction of the DTM, this class will be removed.
 * This class provides a DOM level 2 "helper", which provides services currently
 * not provided be the DOM standard.
 */
public class DOM2Helper extends DOMHelper {

    /**
     * Field m_doc: Document Node for the document this helper is currently
     * accessing or building
     *
     * @see #setDocument
     * @see #getDocument
     */
    private Document m_doc;

    /**
     * Construct an instance.
     */
    public DOM2Helper() {
    }

    /**
     * Figure out whether node2 should be considered as being later
     * in the document than node1, in Document Order as defined
     * by the XPath model. This may not agree with the ordering defined
     * by other XML applications.
     * <p>
     * There are some cases where ordering isn't defined, and neither are
     * the results of this function -- though we'll generally return true.
     * <p>
     * TODO: Make sure this does the right thing with attribute nodes!!!
     *
     * @param node1 DOM Node to perform position comparison on.
     * @param node2 DOM Node to perform position comparison on .
     * @return false if node2 comes before node1, otherwise return true.
     * You can think of this as
     * <code>(node1.documentOrderPosition &lt;= node2.documentOrderPosition)</code>.
     */
    public static boolean isNodeAfter(Node node1, Node node2) {

        // Assume first that the nodes are DTM nodes, since discovering node
        // order is massivly faster for the DTM.
        if (node1 instanceof wx.xml.xalan.xml.utils.DOMOrder && node2 instanceof wx.xml.xalan.xml.utils.DOMOrder) {
            int index1 = ((wx.xml.xalan.xml.utils.DOMOrder) node1).getUid();
            int index2 = ((wx.xml.xalan.xml.utils.DOMOrder) node2).getUid();

            return index1 <= index2;
        } else {

            // isNodeAfter will return true if node is after countedNode
            // in document order. The base isNodeAfter is sloooow (relatively).
            return wx.xml.xalan.xml.utils.DOMHelper.isNodeAfter(node1, node2);
        }
    }

    /**
     * Get the XPath-model parent of a node.  This version takes advantage
     * of the DOM Level 2 Attr.ownerElement() method; the base version we
     * would otherwise inherit is prepared to fall back on exhaustively
     * walking the document to find an Attr's parent.
     *
     * @param node Node to be examined
     * @return the DOM parent of the input node, if there is one, or the
     * ownerElement if the input node is an Attr, or null if the node is
     * a Document, a DocumentFragment, or an orphan.
     */
    public static Node getParentOfNode(Node node) {
        Node parent = node.getParentNode();
        if (parent == null && (Node.ATTRIBUTE_NODE == node.getNodeType()))
            parent = ((Attr) node).getOwnerElement();
        return parent;
    }

    /**
     * Check node to see if it was created by a DOM implementation
     * that this helper is intended to support. This is currently
     * disabled, and assumes all nodes are acceptable rather than checking
     * that they implement wx.xml.xalan.xerces.dom.NodeImpl.
     *
     * @param node The node to be tested.
     * @throws TransformerException if the node is not one which this
     *                              DOM2Helper can support. If we return without throwing the exception,
     *                              the node is compatable.
     * @xsl.usage internal
     */
    public void checkNode(Node node) throws TransformerException {

        // if(!(node instanceof wx.xml.xalan.xerces.dom.NodeImpl))
        //  throw new TransformerException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_XERCES_CANNOT_HANDLE_NODES, new Object[]{((Object)node).getClass()})); //"DOM2Helper can not handle nodes of type"
        //+((Object)node).getClass());
    }

    /**
     * Returns true if the DOM implementation handled by this helper
     * supports the SAX ContentHandler interface.
     *
     * @return true (since Xerces does).
     */
    public boolean supportsSAX() {
        return true;
    }

    /**
     * Query which document this helper is currently operating on.
     *
     * @return The DOM Document node for this document.
     * @see #setDocument
     */
    public Document getDocument() {
        return m_doc;
    }

    /**
     * Specify which document this helper is currently operating on.
     *
     * @param doc The DOM Document node for this document.
     * @see #getDocument
     */
    public void setDocument(Document doc) {
        m_doc = doc;
    }

    /**
     * Parse an XML document.
     *
     * <p>Right now the Xerces DOMParser class is used.  This needs
     * fixing, either via jaxp, or via some other, standard method.</p>
     *
     * <p>The application can use this method to instruct the SAX parser
     * to begin parsing an XML document from any valid input
     * source (a character stream, a byte stream, or a URI).</p>
     *
     * <p>Applications may not invoke this method while a parse is in
     * progress (they should create a new Parser instead for each
     * additional XML document).  Once a parse is complete, an
     * application may reuse the same Parser object, possibly with a
     * different input source.</p>
     *
     * @param source The input source for the top-level of the
     *               XML document.
     * @throws TransformerException if any checked exception is thrown.
     * @xsl.usage internal
     */
    public void parse(InputSource source) throws TransformerException {

        try {

            // I guess I should use JAXP factory here... when it's legal.
            // wx.xml.xalan.xerces.parsers.DOMParser parser
            //  = new wx.xml.xalan.xerces.parsers.DOMParser();
            DocumentBuilderFactory builderFactory =
                DocumentBuilderFactory.newInstance();

            builderFactory.setNamespaceAware(true);
            builderFactory.setValidating(true);

            DocumentBuilder parser = builderFactory.newDocumentBuilder();

      /*
      // domParser.setFeature("http://apache.org/xml/features/dom/create-entity-ref-nodes", getShouldExpandEntityRefs()? false : true);
      if(m_useDOM2getNamespaceURI)
      {
      parser.setFeature("http://apache.org/xml/features/dom/defer-node-expansion", true);
      parser.setFeature("http://xml.org/sax/features/namespaces", true);
      }
      else
      {
      parser.setFeature("http://apache.org/xml/features/dom/defer-node-expansion", false);
      }

      parser.setFeature("http://apache.org/xml/features/allow-java-encodings", true);
      */

            parser.setErrorHandler(
                new wx.xml.xalan.xml.utils.DefaultErrorHandler());

            // if(null != m_entityResolver)
            // {
            // System.out.println("Setting the entity resolver.");
            //  parser.setEntityResolver(m_entityResolver);
            // }
            setDocument(parser.parse(source));
        } catch (org.xml.sax.SAXException se) {
            throw new TransformerException(se);
        } catch (ParserConfigurationException pce) {
            throw new TransformerException(pce);
        } catch (IOException ioe) {
            throw new TransformerException(ioe);
        }

        // setDocument(((wx.xml.xalan.xerces.parsers.DOMParser)parser).getDocument());
    }

    /**
     * Given an XML ID, return the element. This requires assistance from the
     * DOM and parser, and is meaningful only in the context of a DTD
     * or schema which declares attributes as being of type ID. This
     * information may or may not be available in all parsers, may or
     * may not be available for specific documents, and may or may not
     * be available when validation is not turned on.
     *
     * @param id  The ID to search for, as a String.
     * @param doc The document to search within, as a DOM Document node.
     * @return DOM Element node with an attribute of type ID whose value
     * uniquely matches the requested id string, or null if there isn't
     * such an element or if the DOM can't answer the question for other
     * reasons.
     */
    public Element getElementByID(String id, Document doc) {
        return doc.getElementById(id);
    }

    /**
     * Returns the local name of the given node, as defined by the
     * XML Namespaces specification. This is prepared to handle documents
     * built using DOM Level 1 methods by falling back upon explicitly
     * parsing the node name.
     *
     * @param n Node to be examined
     * @return String containing the local name, or null if the node
     * was not assigned a Namespace.
     */
    public String getLocalNameOfNode(Node n) {

        String name = n.getLocalName();

        return (null == name) ? super.getLocalNameOfNode(n) : name;
    }

    /**
     * Returns the Namespace Name (Namespace URI) for the given node.
     * In a Level 2 DOM, you can ask the node itself. Note, however, that
     * doing so conflicts with our decision in getLocalNameOfNode not
     * to trust the that the DOM was indeed created using the Level 2
     * methods. If Level 1 methods were used, these two functions will
     * disagree with each other.
     * <p>
     * TODO: Reconcile with getLocalNameOfNode.
     *
     * @param n Node to be examined
     * @return String containing the Namespace URI bound to this DOM node
     * at the time the Node was created.
     */
    public String getNamespaceOfNode(Node n) {
        return n.getNamespaceURI();
    }

    /** Field m_useDOM2getNamespaceURI is a compile-time flag which
     *  gates some of the parser options used to build a DOM -- but
     * that code is commented out at this time and nobody else
     * references it, so I've commented this out as well. */
    //private boolean m_useDOM2getNamespaceURI = false;
}
